In Apache Spark, the Resilient Distributed Dataset (RDD) is a core abstraction that represents an immutable, distributed collection of objects that can be processed in parallel. When you perform multiple actions on the same RDD, Spark will recompute the entire lineage of that RDD each time an action is invoked. This can be inefficient, especially …
Why Do We Need to Call Cache or Persist on an RDD in Apache Spark? Read More »
Adding a new column to a Spark DataFrame in PySpark is a common operation you might need in data processing. You can achieve this in several ways, depending on your specific needs. Below, I’ll explain a couple of methods, along with code snippets and their expected output. Method 1: Using the `withColumn` Method The `withColumn` …
How to Add a New Column to a Spark DataFrame Using PySpark? Read More »
Reading multiple text files into a single RDD in Apache Spark is a common task, especially when you’re dealing with a large amount of data distributed across multiple files. This can be efficiently done using the `textFile` method available in the SparkContext or SparkSession. Below, I’ll provide examples using PySpark, Scala, and Java. Reading Multiple …
How to Read Multiple Text Files into a Single RDD in Apache Spark? Read More »
Disabling info logging in Apache Spark can be beneficial when you want to reduce the verbosity of logs and focus on more critical log levels like warnings or errors. This guide will explain how you can turn off info logging in Spark using various languages and configurations. Step-by-Step Guide to Turn Off Info Logging in …
How to Turn Off Info Logging in Spark: A Step-by-Step Guide Read More »
Concatenating columns in an Apache Spark DataFrame can be done using various methods depending on the programming language you are using. Here, I’ll illustrate how to concatenate columns using PySpark and Scala. These examples will show you how to combine two or more columns into a new single column. Using PySpark In PySpark, you can …
How to Concatenate Columns in Apache Spark DataFrame? Read More »
To sort by a column in descending order in Spark SQL, you can use the `ORDER BY` clause with the `DESC` keyword. You can run a SQL query using Spark SQL after creating a temporary view of your DataFrame or directly using the DataFrame API in PySpark, Scala, or Java. Below are examples in PySpark …
How to Sort by Column in Descending Order in Spark SQL? Read More »
Spark jobs are executed in a distributed fashion and they are broken down into smaller units of work known as stages and tasks. Understanding how stages are split into tasks is crucial for optimizing performance and debugging issues. Let’s dive into the details. Stages and Tasks in Spark Spark breaks down its job execution flow …
Changing column types in Spark SQL’s DataFrame can be easily achieved using the `withColumn` method in combination with the `cast` function. This method is very handy when you need to ensure that the column types are appropriate for your analysis or processing. Below are examples in both PySpark and Scala. Changing Column Types in PySpark …
How Can I Change Column Types in Spark SQL’s DataFrame? Read More »
Filtering a PySpark DataFrame to remove rows where a specific column contains `None` values is a very common operation. This can be achieved using the `filter()` or `where()` methods provided by PySpark. Below is a detailed explanation along with code snippets on how to accomplish this task. Using filter() or where() Methods You can use …
How to Filter PySpark DataFrame Column with None Values? Read More »
When writing a single CSV file using Spark, the challenge is that Spark by default writes multiple part files. This behavior occurs because Spark processes data in parallel across multiple nodes, and each task writes its own part file. To ensure that the data is written to a single CSV file, you typically need to …
